Telephone system.



J. L. McQUARRIE & H P. CLAUSEN. THEPHONE SYSTEM 1 296 679 APPLICATIGNmen mm. m1. Pat nted Ma 11.1919

lm/en fora: James L. MUuarn'e. Henry 1? Clause/v. by

QR .L m w mrnufm 7 ing the flow of ringing current.

UNITED STATES PATENT OFFICE.

J AMES LFMOQUARRIE, OF MONTCLAIB, NEW JERSEY, AND HENRY P. CLAUSEN, OF

MOUNT VERNON, NEW YORK, ABSIGNORS TO WESTERN ELECTRIC COMPANY, INCOR-POEATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Mar. 11, 1919.

Application filed August 2, 1917. Serial No. 184,028.

To all whom it may concern:

Be it known that we, JAMES L. MCQUAR- IIIE and HENRY P. CLAUSEN,citizens of the United States, residing at Montclair, in the county ofEssex and State of New Jersey, and at Mount Vernon, .in the county ofWestchcsterand State of New York, have invented certain new and usefulImprovements in Telephone Systems, of which the following is a full,clear, concise, and exact description.

This invention relates to telephone systems, and particularly to systemswherein machine-ringing of called subscribers is employed.

It is the practice to signal a called party by intermittently ringingthe bell at the substation. This is'done automatically b'y a ringinmaghin'e at the connector, such machine aying a commutator on the shaftor equivalent means for intermittently break- It frequently happens thatthe brushes of a connector are set on the terminals of a wanted lineduring what is known as thesilent interval of the ringing machine, thatis, during the interval when ringing current is cut ofi from the line,and battery current is substituted. This results in loss of time and isconsidered a disadvantage in commercial systems.

The object of-this invention is to provide a cireuitarrangement wherebringing cur- ,rent is applied to'the called line for a short.

interval immediately after the connector is set thereon, andintermittently thereafter, if the called subscriber does not respond tosuch reliminary signal.

A eatureof the present invention is a ringing. relay arranged to releaseslowly when energized over one circuit, and to release quickly whenenergized over another circuit. According to this feature, therelay isinitially energized, immediately after the called line is seized, insuch a manner that it will release slowly, and thereby apply ringingcurrent to the called line for a definite interval. When, thereafter, itis enerized over a circuit including an interrupter, 1ts: energizationis such that it releases quickly and moves its armatures in synchronismwith the interrupter.

It is thou ht the invention will be better understood y reference totheaccompanying drawing in which a connection between two substations,through the use of a conthrough the apparatus of the subscriberssubstation S, the upper limb of the telephone line, the upper armatureand normal contact of the line relay LR the upper winding of line relayLR, to battery and groundv The line relay LR attracts its armature andestablishes a circuit from ground, the armature and alternate contact ofrelay LR the winding of first slow relay FS, to battery and ground.

The first slow relay FS attracts its arma tures and laces a ground onthe third conductor of t e seized connector switch, whereby otherselector switches are prevented from extending connections thereto. Thisground, extends through the contact and outer armature of relay FS tothe terminal t. v

At the same time, a circuit is prepared for slow relay, being slow torelease, remains energised. throughout the sending of the impulses, butthe primary magnet PM not having such characteristics, responds to eachseparate impulse, and, through its actuation, drives the brushes-b, band b into association with the group of terminals in which are includedthose connected to the substa tion S. The actuation of the second slowrelay SR establishes a circuit from ground, the ih'matm-e and alternatecontact of relay SR, the winding of escape magnet E, to battery andground, whereby the relay E is energized.

l'pou the termination of this series of impulses. the second slow relaySR is d energized, due to the. comparatively have interval during whichthe line relay LR holds its rmature in the attracted position. Theconsequent. det nergization of the escape magnet E causes the movementof the side switch wipers into their second position.

It should be noted at this point that. upon the first movement of thebrushes caused b the primary ma net PM, the primary normal contacts..()N are actuated, and the release magnet RM connected with the normalcontact of the inner left-hand armature of relay FS so that, if, at anytime after the connector switch (S has been seized, the relay LRretracts its armature for a sufficient length of time to allow the firstlow relay F8 to del nergizc, the release magnet will be energized andcause the restoration of the connector switch.

The last set of impulses sent out by the dial switch D causes theenergization of the secondary magnet SM and the second slow relay Sthrough a circuit extending now from the winding of second slow relay SRthrough the a per contact and armature of the test reniy R, winding ofsecondary magnet SM. second position contact and side-switch wiper W tobattery and "round. Since the functioning of the test relay TR forms nopart of the present invention, and since its operation is well known andcan be easily followed from the drawing. no further description will begiven. Responsive to the impulses flowing through the circuit justdescribed, the secondary magn SM moves the brushes 1) to I) inclusiveinto association with the tel inals t to t inclusive. whereby the linesleading to substation S (assumed to be idle) are seized: At thetermination of this series of impulses. the escape magnet E is again deinergized and the side switch wipers are movedinto their third positions.

In the third positiifh, a circuit is established from ground,side-switch wiper WV and its third p ition contact. wim ing of relay 1,battery and ground, whereby relay 55 1 is energized nd attracts itsarmatures to ,extend the talking conductors, ieadin from the armatu'resof the ringing relay R, to

the b shes b" and b respectively.

Ifiph uld be noted that while in the secand position the side-switchwiper W entended a connection from ground through the upper winding ofrelay RR, to battely anl, ground. The upper winding of relay RR iss'd'wolmd thaheg ufh current flows 66 through the circuit just s lfibedtqnot only energize the relay but to cause it to be slow to release whenthis current ceases to flow. As the side switch is moved into the thirdposition, a circuit is then established, by the energization of relay 1,extending from ground, the ringing current generator G, the alternatecontact and upper armature of the relay RR. the upper armature andcontact of relay 1, brush 1), terminal t, to and through the call bellof the substation S terminal f brush b the contact and lower armature ofrelay 1, the inner lower armature and alternate contact of relay RR. toground. The relay RR. being slow to release, maintains this circuit fora definite interval.

ytT-ythe third position of the side switch is reac ed a circuit is alsoestablishetl from ground, the side-switch wiper W and it third positioncontact, outer lower armature and contact of relay RR, the side-switchwiper \V and its third position contact, the winding of escape magnet E,to battery and ground. When the relay RR finally releases its armatures.the described circuit for the energization of escape magnet E is opened,the escape magnet deinergizes, and the sideswitch wipers more into-theirfourth position.

In the fourth position, a circuit is established from ground, theinterrupter I, the lower winding of relay RR, contact and upper armatureof the clay 2. the fourth position contact and si e-switch wiper \V{, tobattery, and round. The lower winding of release re ay RR is soproportioned that the current flow in this circuit, while sutlicient tocause its energization. is insutiieient to impart the slow releasingcharacteristic, this bein a function of the ampere turns, as is weknown. Through this circuit. relay RR is intermittently energized andtit-energized. and. in response. it intermittently attracts and retractsits armatures. When, in res onse to the-summons of his callbell, the suscriber at substation S remores his receiver from the hook and the relayR-R next becomes deenergized, a circuit is established from ground, thelower winding of relay LR, the lower talking conductor of the connectorswitch, the normal contact and inner lower armature of relay RR, thelower armature and contact of relay 1, the brush teianinal t, to andthrough the apparatus-of the substation S", the terminal t. brush 1),contact and upper armature of relay 1, the upper armature and normalcontact of the relay RR, the upper talking conductor of the connectorswitch, the upper winding of relay LR, to battery and ground. Relay LRattracts its at-matures and establishes a circuit from ground, the lowercontact of PON, the lower armature and contact of relay LR, thewindingof relay 2, the fourth position contact and sideswitch wiper W,to battery and ground. The consequent energization of relay 2 opens theenergizing circuit of the relay RR at the upper armature and contact ofrelay :2, and closes a holding circuit for itself through its contactand lower armature in parallel with the contact and lower armature ofrelay LR.

The relay 1 is maintained energized, during the conversation, through acircuit extending from ground, fourth position contact and side-switchwiper W, the armature and contact of escape magnet E, the

winding of relay 1, to battery and ground.

At the close of the conversation, the deenergization of relay LR causesthe deiinergization of the first slow relay FS, which establishes acircuit from ground, armature and normal contact of relay LE innerarmature and normal contact of the relay FS, upper contact of PON,through the winding of the release magnet RM, to battery and ground,whereupon the connector switch is released in the well known manner. Theremoval of the ground potential from the terminal at through thedeiinergization of the first slow rela FS allows the release of theselector switc SS.

What is claimed is:

1. In a telephone system, the combination with telephone lines, a callbell associated with each of said lines, switching means forinterconnecting said lines and a source of ringing current for actuatingsaid call bells, of a slow-releasing relay having two windings includedin said switching means for controlling the application of said ringingcurrent to said lines, a transient circuit including one of said.windings for the energization of said relay established upon the seizureof one of said lines as a called line by said means, and a circuitincluding an interrupter and the other of said windings for thesubsequent energization of said relay.

2. In a telephone system, the combination with telephone lines, a callbell associated with each of said lines, a connector switch in whichsaid lines terminate, means for setting said connector switch on saidlines and a source of ringing current for actuating said call bells, ofa relay having two windings for controlling the application of saidringing current to said lines, a transient circuit including one of saidwindings for the initial energization of said relay, and a circuitincluding an interrupter and the other of said windings for thesubsequent energization of said relay.

3. In a telephone system, the combination with telephone lines, a sourceof ringing current and switching means for interconnecting said lines,of a slow-releasing relay for controlling the application of saidcurrent to said lines, a transiently-established circuit for the initialenergization of said relay, a circuit including an interrupter for thesub sequent energization of said relay, and means included in said lastcircuit for reducing the flow of current therover for causing said relayto be quick to release.

4. In a telephone system, the combination with telephone lines, a sourceof ringing current, switching means for interconnecting said lines, of arelay for controlling the application of said current to said lines, atransientl -established circuit including means for t estrongenergization of said relay and a circuit including an interrupter meansfor the weak energization of said relay.

5. In a telephone system the combination with telephone lines, a callbell associated with each of said lines, a connector switch in whichsaid lines terminate, means for setting said connector switch on saidlines and a source of ringing current for actuating said call bells, ofa relay having a high resistance and a low resistance winding forcontrolling the application of said ringing current to said lines, atransient circuit including the low resistance winding of said relay,for the initial energization of said relay, and a circuit includm aninterrupter'and said high resistance winding of said relay for thesubsequent energization of said relay.

In witness whereof, we hereunto subscribe our names this 1st day ofAugust-A D., 1917.

JAMES L. MCQUARRIE.

HENRY P. CLAUSEN.

